neutralhadron

Neutral hadrons are hadrons with zero electric charge. Hadrons are composite particles made of quarks bound by the strong force, and they come in two families: baryons (three quarks) and mesons (a quark–antiquark pair). Neutral hadrons include the neutron, as well as neutral mesons such as the pi-zero (π0), eta (η), eta-prime (η′), and neutral kaons (K0 and anti-K0), along with heavier neutral resonances and neutral members of baryon multiplets.

Key examples and properties: The neutron is a neutral baryon with mass about 939 MeV and a free lifetime of roughly 880 seconds before beta decay. The pi-zero is the lightest neutral meson and decays electromagnetically to two photons in about 8×10^-17 seconds. Neutral kaons (K0 and K̄0) are strange mesons that mix to form short-lived and long-lived states, K_S and K_L, with lifetimes on the order of 10^-10 to 10^-8 seconds and decays via the weak interaction. The Lambda-zero (Λ0) and Sigma-zero (Σ0) are neutral baryons; Σ0 decays electromagnetically to Λ0 and a photon, while Λ0 decays weakly into lighter particles.

Interactions and detection: Neutral hadrons participate in strong interactions when present as constituents or during hadronization, and they can undergo electromagnetic or weak processes depending on the particle. Detection often relies on observing decay products or secondary interactions, since charged tracks are not directly produced by neutral hadrons.

Significance: Neutral hadrons are essential in studies of nuclear structure, hadronization, CP violation, and particle interactions produced in high-energy collisions and cosmic processes.